The Diabetes in Self-Control (DISC) system is a comprehensive microcomputer-based system to facilitate patient self-control of insulin-requiring diabetes mellitus. DISC consists of a data management and review system, diabetes education modules, and diabetes problem-solving and goal-setting. A pocket computer ("electronic log") will prompt DISC users to record information about blood glucose levels, insulin, weight, diet, exercise, and emotional and physical stress. The log will be periodically interfaced with the microcomputer to transmit data for compilation and subject review. The diabetes education component of DISC will be organized into 3 broad levels (Survival Skills; Management Skills; Lifestyle Changes) to enhance subject ability to self-pace learning. Additional graphics will be added to the text. The education component developed in Phase I for adolescents will be modified for adults. Readability will be at the fourth grade level. There will be two 6-month experimental periods. Fifty insulin dependent adolescents and 30 insulin-requiring adults will be equally divided into the DISC groups and the no-intervention control groups. The effectiveness of the DISC system for newly diagnosed adolescents will be evaluated with 5 to 10 subjects. Measures evaluated include: glycosylated hemoglobin, frequency and levels of blood glucose tests, diabetes knowledge, management behaviors and subject participation in diabetes control.